US4240840A
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Cementitious compositions
Assignee: Imperial Chemical Industries Ltd
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Filing: 1978-04-26
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Granted: 1980-12-23
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Expires: 1998-04-26
Abstract
Abstract Cementitious compositions having a modulus of rupture greater than 20 MN/m2 are prepared by subjecting a mixture of hydraulic cement, fine aggregate, a selected water-dispersible polymer and water to a homogenization process (in order to very substantially reduce voidage in the product) and by thereafter curing and drying the product. The aggregate improves the modulus of rupture and resists any loss in this strength property due to moisture uptake and loss.
Inventors
- 👤 Stephen B. Downing
- 👤 Desmond W. J. Osmond
- 👤 Maurice W. Skinner
- 👤 Edmund J. West
- 👤 David G. Dawson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:47
CPC Classifications
C; C04; C04B; C04B28/00; C04B28/02; C04B28/06
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
239 words
A homogeneous uncured cementitious composition which comprises the following initial ingredients: (a) a hydraulic cement selected from the group consisting of cements which comprise compounds of calcium, aluminum, silicon, oxygen and/or sulfur which set and harden by reaction with water, (b) water, (c) a water-dispersible polymer, and (d) a fine aggregate of which 75% by weight passes a sieve of aperture 1 mm; wherein (i) the ratio of water to hydraulic cement is in the range 10-28 parts by weight of water to 100 parts hydraulic cement; (ii) the water-dispersible polymer is selected with reference to the hydraulic cement and to the selected proportions of water, cement and fine aggregate for its suitability to facilitate homogenization and to yield on homogenization a product which can be shaped under pressure and which is shape-retaining; (iii) the ratio of water-dispersible polymer to hydraulic cement is in the range 0.1-3.0 parts by weight of water-dispersible polymer to 100 parts by weight of hydraulic cement; and (iv) the amount of fine aggregate (d) is 5% to 75% by weight based on the weight of hydraulic cement; and wherein the ingredients (a), (b), (c) and (d) have been jointly subjected to a homogenization process of dispersion and homogenization so that they are regularly dispersed throughout the composition such that on curing and drying, the homogeneous uncured composition yields a cured, dried cementitious material having a modulus of rupture greater than 20 MN/m 2 .
Claim 2
Dependent Claim
239 words
A homogeneous uncured cementitious composition which comprises the following initial ingredients: (a) a hydraulic cement selected from the group consisting of cements which comprise compounds of calcium, aluminum, silicon, oxygen and/or sulfur which set and harden by reaction with water, (b) water, (c) a water-dispersible polymer, and (d) a fine aggregate of which 75% by weight passes a sieve of aperture 1 mm; wherein (i) the ratio of water to hydraulic cement is in the range 10-28 parts by weight of water to 100 parts hydraulic cement; (ii) the water-dispersible polymer is selected with reference to the hydraulic cement and to the selected proportions of water, cement and fine aggregate for its suitability to facilitate homogenization and to yield on homogenization a product which can be shaped under pressure and which is shape-retaining; (iii) the ratio of water-dispersible polymer to hydraulic cement is in the range 0.1-3.0 parts by weight of water-dispersible polymer to 100 parts by weight of hydraulic cement; and (iv) the amount of fine aggregate (d) is 5% to 75% by weight based on the weight of hydraulic cement; and wherein the ingredients (a), (b), (c) and (d) have been jointly subjected to a homogenization process of dispersion and homogenization so that they are regularly dispersed throughout the composition such that on curing and drying, the homogeneous uncured composition yields a cured, dried cementitious material having a modulus of rupture greater than 20 MN/m 2 .
Claim 3
Dependent Claim
19 words
A composition according to claim 1 wherein 100% of the fine aggregate passes a sieve of aperture 1 mm.
Claim 4
Dependent Claim
23 words
A composition according to claim 1 wherein the major proportion of the fine aggregate has a particle diameter of greater than 1 μm.
Claim 5
Dependent Claim
25 words
A composition according to claim 1 wherein there is present up to 75% of fine aggregate by weight based on the weight of hydraulic cement.
Claim 6
Dependent Claim
24 words
A composition according to claim 1 wherein the fine aggregate is selected from a silica-containing material, a magnesium silicate-containing material or an alumina-containing material.
Claim 7
Dependent Claim
26 words
A composition according to claim 1 wherein the fine aggregate is selected from silica sand, silica flour, slate powder, olivine sand, olivine flour, or calcined bauxite.
Claim 8
Dependent Claim
34 words
A composition according to claim 1 wherein the water dispersible polymer is selected from alkyl and hydroxyalkyl cellulose ethers, homopolymers and copolymers of acrylamide or methacrylamide, homopolymers and copolymers of ethylene oxide, and polyvinylpyrrolidone.
Claim 9
Dependent Claim
32 words
A composition according to claim 1 wherein the water-dispersible polymer is selected from methyl cellulose, hydroxy ethyl cellulose, methylhydroxyethyl cellulose, ethyl hydroxyethyl cellulose, hydroxy-propyl cellulose, hydroxypropyl methyl cellulose and hydroxybutyl methyl cellulose.
Claim 10
Dependent Claim
16 words
A composition according to claim 1 which comprises a fibre other than an inorganic mineral fibre.
Claim 11
Dependent Claim
14 words
A composition according to claim 9 wherein the fibre is of nylon or polypropylene.
Claim 12
Dependent Claim
12 words
A composition according to claim 9 wherein the fibre is glass fibre.
Claim 13
Independent Claim
263 words
A method of preparing a homogeneous uncured cementitious composition which comprises the following initial ingredients: (a) a hydraulic cement selected from the group consisting of cements which comprise compounds of calcium, aluminum, silicon, oxygen and/or sulfur which set and harden by reaction with water, (b) water, (c) a water-dispersible polymer, and (d) a fine aggregate of which 75% by weight passes a sieve of aperture 1 mm; wherein (i) the ratio of water to hydraulic cement is in the range 10-28 parts by weight of water to 100 parts hydraulic cement; (ii) the water-dispersible polymer is selected with reference to the hydraulic cement and to the selected proportions of water, cement and fine aggregate for its suitability to facilitate homogenization and to yield on homogenization a product which can be shaped under pressure and which is shape-retaining; (iii) the ratio of water-dispersible polymer to hydraulic cement is in the range 0.1-3.0 parts by weight of water-dispersible polymer to 100 parts by weight of hydraulic cement; and (iv) the amount of fine aggregate (d) is 5% to 75% by weight based on the weight of hydraulic cement; and wherein the ingredients (a), (b), (c) and (d) have been jointly subjected to a homogenization process of dispersion and homogenization so that they are regularly dispersed throughout the composition such that on curing and drying, the homogeneous uncured composition yields a cured, dried cementitious material having a modulus of rupture greater than 20 MN/m 2 wherein the ingredient (a), (b), (c), and (d) are jointly subjected to a homogenisation process comprising a high shear mixing process.
Claim 14
Independent Claim
263 words
A method of preparing a homogeneous uncured cementitious composition which comprises the following initial ingredients: (a) a hydraulic cement selected from the group consisting of cements which comprise compounds of calcium, aluminum, silicon, oxygen and/or sulfur which set and harden by reaction with water, (b) water, (c) a water-dispersible polymer, and (d) a fine aggregate of which 75% by weight passes a sieve of aperture 1 mm; wherein (i) the ratio of water to hydraulic cement is in the range 10-28 parts by weight of water to 100 parts hydraulic cement; (ii) the water-dispersible polymer is selected with reference to the hydraulic cement and to the selected proportions of water, cement and fine aggregate for its suitability to facilitate homogenization and to yield on homogenization a product which can be shaped under pressure and which is shape-retaining; (iii) the ratio of water-dispersible polymer to hydraulic cement is in the range 0.1-3.0 parts by weight of water-dispersible polymer to 100 parts by weight of hydraulic cement; and (iv) the amount of fine aggregate (d) is 5% to 75% by weight based on the weight of hydraulic cement; and wherein the ingredients (a), (b), (c) and (d) have been jointly subjected to a homogenization process of dispersion and homogenization so that they are regularly dispersed throughout the composition such that on curing and drying, the homogeneous uncured composition yields a cured, dried cementitious material having a modulus of rupture greater than 20 MN/m 2 wherein the ingredient (a), (b), (c), and (d) are jointly subjected to a homogenisation process comprising a high shear mixing process.
Claim 15
Dependent Claim
30 words
A cured and dried cementitious composition comprising cured hydraulic cement, a fine aggregate and a water dispersible polymer which has a modulus of rupture greater then 20 MN/m 2 .
Claim 16
Dependent Claim
30 words
A cured and dried cementitious composition comprising cured hydraulic cement, a fine aggregate and a water dispersible polymer which has a modulus of rupture greater then 20 MN/m 2 .
Claim 17
Dependent Claim
32 words
A cured and dried cementitious composition according to claim 13 which also comprises a fibre in a proportion not greater than the critical volume of that fibre with respect to the composition.
Claim 18
Dependent Claim
15 words
A shaped article which comprises a cured and dried cementitious composition according to claim 13.
Claim 19
Dependent Claim
23 words
A homogeneous uncured cementitious composition as set forth in claim 1 wherein the ingredients (a), (b), (c) and (d) have been jointly shaped.
Claim 20
Dependent Claim
20 words
A method as set forth in claim 12 wherein the high shear mixing process comprises an extrusion or calendering process.
Claim 21
Dependent Claim
23 words
A method as set forth in claim 12 in which the high shear mixing process is followed by an extrusion or calendering process.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-23 | 1984-06-23 | 1984-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-23 | 1988-06-23 | 1988-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-23 | 1992-06-23 | 1992-12-23 | $7700.00 | Window Closed / Lapsed |